What is the purpose of the role attribute at episode of care resource

what is the purpose of the role attribute at an episode of care resource?

how can that role be useful in a real-world scenario? and what is the appropriate way to use it?

Do you mean EpisodeOfCare.diagnosis.role ?

It supports saying how a diagnosis is related to the episode of care. Maybe a patient is admitted with a diagnosis of appendicitis and discharged with a diagnosis of bowel cancer.